Factorio Forums

In Alt-view you can see icons on furnaces, which indicate which type of item is smelting. I found a way to make them disappear, although in both input and output slots have items.

How to reproduce? One image is worth 1000 words. This happens every time on this save, even if I remove furnace and build it again. However, I didn't manage to reproduce this in a new game. (Maybe I did something differently.) This save was originally created in version 0.15.1.

That is normal, when no recipe is performed no indicator is displayed.